Imatinib induced severe skin reactions and neutropenia in a patient with gastrointestinal stromal tumor

BACKGROUND

Imatinib mesylate has been used for the treatment of unresectable or metastatic gastrointestinal stromal tumors (GIST). The current recommended dose of imatinib is 400 mg/day that is increased to 800 mg/day in cases with disease progression. However, imatinib can be associated with diverse adverse events, which has limited its use. We report a case of severe adverse skin reactions with neutropenic fever during imatinib treatment in a patient with GIST.

CASE PRESENTATION

A 71-year-old man was admitted with a one month history of epigastric pain and a palpable mass in the right upper quadrant. An abdominal CT scan revealed a 20 x 19 cm intraabdominal mass with tumor invasion into the peritoneum. Needle biopsy was performed and the results showed spindle shaped tumor cells that were positive for c-KIT. The patient was diagnosed with unresectable GIST. Imatinib 400 mg/day was started. The patient tolerated the first eight weeks of treatment. However, about three months later, the patient developed a grade 4 febrile neutropenia and a grade 3 exfoliative skin rash. The patient recovered from this serious adverse events after discontinuation of imatinib with supportive care. However, the skin lesions recurred whenever the patient received imatinib over 100 mg/day. Therefore, imatinib 100 mg/day was maintained. Despite the low dose imatinib, follow up CT showed a marked partial response without grade 3 or 4 toxicities.

CONCLUSION

The recommended dose of imatinib for the treatment of GIST is 400 mg/day but patients at risk for adverse drug reaction may benefit from lower doses. Individualized treatment is needed for such patients, and we may also try sunitinib as a alternative drug.

Femoral lengthening in achondroplasia: magnitude of lengthening in relation to patterns of callus, stiffness of adjacent joints and fracture

Extensive limb lengthening may be indicated in achondroplastic patients who wish to achieve a height within the normal range for their population. However, increasing the magnitude of lengthening is associated with further complications particularly adjacent joint stiffness and fractures. We studied the relationship between the magnitude of femoral lengthening and callus pattern, adjacent joint stiffness and fracture of the regenerate bone in 40 femoral lengthenings in 20 achondroplastic patients. They were divided into two groups; group A had lengthening of less than 50% and group B of more than 50% of their initial femoral length. The patterns of radiological callus formation were classified according to shape, type and features. The incidence of callus features, knee stiffness and regenerate bone fracture were analysed in the two groups. Group B was associated with an increased incidence of concave, lateral and central callus shapes, adjacent joint and stiffness and fracture. Statistically, the incidence of stiffness in adjacent joints and regenerate bone fracture was significantly associated with the magnitude of lengthening. We suggest that careful radiological assessment of the patterns of callus formation is a useful method for the evaluation and monitoring of regenerate bone.

Phase II study of S-1 monotherapy in paclitaxel- and cisplatin-refractory gastric cancer

PURPOSE

S-1 is a fourth-generation oral fluoropyrimidine that was developed to mimic the effects achieved with protracted continuous infusion of 5-fluorouracil (5-FU). This phase II study evaluated the efficacy and safety of S-1 salvage chemotherapy in patients with paclitaxel- and cisplatin-refractory gastric cancer. The primary end point was progression-free survival; secondary end points were overall survival, safety, and clinical benefit.

METHODS

Patients were eligible for the study if they had histologically documented gastric adenocarcinoma previously treated with paclitaxel and cisplatin, age > or = 18 years, Eastern Clinical Oncology Group performance status < or =2, adequate organ function, and no evidence of gastrointestinal obstruction or passage disturbance. Patients were treated with a dose of S-1 based on body surface area (BSA) as follows: BSA < 1.25 m(2), 80 mg/day; 1.25 < or = BSA < 1.5 m(2), 100 mg/day; BSA > or= 1.5 m(2), 120 mg/day. The total dose was divided in two and administered twice daily for 4 weeks followed by a 2-week rest period.

RESULTS

Of the 53 patients enrolled in this study, 49 were evaluable. A total of 190 chemotherapy cycles were administered, and the median number of cycles was 2. Five patients (9.4%) had a partial response, and 18 (34%) had stable disease. Median progression-free survival and overall survival were 4.9 and 10.4 months, respectively. Grade 3/4 hematological toxicities included neutropenia in six patients (11%) but no cases of febrile neutropenia were found. Most of the non-hematological toxicities were diarrhea, asthenia, and mucositis, but none reached grade 3 or grade 4 in severity. Improvement of pain was observed in 17 patients (32.1%).

CONCLUSIONS

S-1 monotherapy provides active and safe salvage chemotherapy for patients with advanced gastric cancer who have been previously treated with paclitaxel and cisplatin.

Wnt5a Is Required for Endothelial Differentiation of Embryonic Stem Cells and Vascularization via Pathways Involving Both Wnt/β-Catenin and Protein Kinase Cα

In this study, we examined the signaling pathways activated by Wnt5a in endothelial differentiation of embryonic stem (ES) cells and the function of Wnt5a during vascular development. We first found that Wnt5a −/− mouse embryonic stem (mES) cells exhibited a defect in endothelial differentiation, which was rescued by addition of Wnt5a, suggesting that Wnt5a is required for endothelial differentiation of ES cells. Involvement of both β-catenin and protein kinase (PK)Cα pathways in endothelial differentiation of mES cells requiring Wnt5a was indicated by activation of both β-catenin and PKCα in Wnt5a +/− but not in Wnt5a −/− mES cells. We also found that β-catenin or PKCα knockdowns inhibited the Wnt5a-induced endothelial differentiation of ES cells. Moreover, the lack of endothelial differentiation of Wnt5a −/− mES cells was rescued only by transfection of both β-catenin and PKC α, indicating that both genes are required for Wnt5a-mediated endothelial differentiation. Wnt5a was also found to be essential for the differentiation of mES cells into immature endothelial progenitor cells, which are known to play a role in repair of damaged endothelium. Furthermore, a defect in the vascularization of the neural tissue was detected at embryonic day 14.5 in Wnt5a −/− mice, implicating Wnt5a in vascular development in vivo. Thus, we conclude that Wnt5a is involved in the endothelial differentiation of ES cells via both Wnt/β-catenin and PKC signaling pathways and regulates embryonic vascular development.

The complete genome sequence of pepper severe mosaic virus and comparison with other potyviruses

The complete nucleotide sequence of pepper severe mosaic virus (PepSMV) was determined. The viral genome consisted of 9890 nucleotides, excluding a poly (A) tract at the 3' end of the genome. The PepSMV RNA genome encoded a single polyprotein of 3085 amino acid residues, resulting in ten functionally distinct potyviral proteins. The lengths of the 5' nontranslated region (NTR) and the 3' NTR were 164 and 468 nucleotides, respectively. The genome organization of the virus was typical for members of the genus Potyvirus in the family Potyviridae. The coat protein amino acid sequence identity between PepSMV and the other 45 potyviruses ranged from 53.4 to 79.7%. Sequence alignments and phylogenetic analyses of the potyviral polyprotein sequences revealed that PepSMV was the closest to potato virus Y (PVY) and closely related to members of the PVY subgroup. Our genome sequence data clearly confirmed that PepSMV belongs to a separate species in the genus Potyvirus.

Duration curve analysis for the assessment of pathogen loading from diffuse sources

Pathogen level of surface waters has received great attention for protecting public health. In this study, total coliform, fecal coliform and Escherichia coli concentrations were monitored as the pathogen indicator organisms at six monitoring stations in the Geum River, Korea. Rainfall runoff from two agricultural-forestry watersheds was analyzed for their microbial aspect as well. Total coliform concentration of the Geum River showed high correlation with the flow rate. To estimate total coliform loading on the Geum River in probability scale, the duration curve method was applied. In addition, a standard duration curve reflecting the water quality criteria was constructed to determine water quality compliance. Under the assumption of linearity between flow rate and total coliform concentration of the Geum River, total coliform duration curve revealed that total coliform concentrations exceed the desired criteria mainly due to pollutants from diffuse sources.

Zantedeschia mosaic virus causing leaf mosaic symptom in calla lily is a new potyvirus

Anovel virus, Zantedeschia mosaic virus (ZaMV-KR), causing mosaic and malformation symptoms was isolated from calla lily ( Zantedeschia spp.) in Korea and its biological and molecular properties were characterized. The virus was distinct from Dasheen mosaic virus, an Araceae-infecting potyvirus, by serological and sequence analyses. Multiple alignments of the CP amino acid sequence between the virus and other potyviruses showed 51.8 to 62.1% identity. Phylogenetic analyses of the CP revealed that the virus could be clustered with Plum pox virus and Turnip mosaic virus. Sequence comparison of the CP gene between the virus and three other ZaMV isolates from Taiwan showed over 93.9% identity, and most of amino acids changes occurred in the N-terminal region. Sequence comparison of 3' NTR revealed homology levels of 27.0 to 47.9% between the virus and other potyviruses. Our results support ZaMV as a distinct species of the genus Potyvirus.

Completion of nucleotide sequence and generation of highly infectious transcripts to cucurbits from full-length cDNA clone of Kyuri green mottle mosaic virus

The nucleotide sequence of the genome of the type strain of Kyuri green mottle mosaic virus (KGMMV-C1) has been completely determined. The genome structure and sequence of the virus were compared to those of Yodo strain of KGMMV (KGMMV-Y). The genome of KGMMV-C1 is 6,514 nucleotides long consisting of 5' and 3' nontranslated regions (NTRs) and four open reading frames coding for 131 kDa and 189 kDa viral replicases, 28 kDa movement protein and 17 kDa coat protein. The nucleotide and amino acid sequences identities of the four encoded proteins and two NTRs between KGMMV-C1 and KGMMV-Y were 85.6% to 93.9% and 87.6% to 95.5%, respectively. Full-length cDNA of KGMMV-C1 was directly amplified by reverse-transcription polymerase chain reaction (RT-PCR) with a set of S'-end primer anchoring T7 RNA promoter sequence and 3'-end primer. This full-length RT-PCR product allowed RNA to be transcribed in vitro. The T7 promoter-anchored RT-PCR product was cloned and used as templates for transcription for plant inoculation test. Capped transcript RNAs transcribed from the full-length cDNA clone as well as capped transcript RNAs from the uncloned RT-PCR products were infectious and caused symptoms characteristic of KGMMV when mechanically inoculated to systemic host plants such as zucchini squash, cucumber and Nicotiana benthamiana. Transcript-derived progeny virus was indistinguishable from the wild-type virus with the same biological and biochemical properties. To our knowledge, this is the first report of the generation of a biologically active KGMMV clone, driven by the T7 promoter, that is highly infectious to cucurbitaceous plants.

N-nitrosocarbofuran, but not carbofuran, induces apoptosis and cell cycle arrest in CHL cells

Carbofuran (CF) is one of the most widely used carbamate pesticides in the world applied for insect and nematode control. Due to its widespread use in agriculture and households, contamination of food, water, and air has become serious, and consequently adverse health effects are inevitable in humans, animals, wildlife and fish. It has been reported that CF alone or in combination with other carbamate insecticides influences the level of reproductive and metabolic hormones such as thyroxine and corticosterone, and results in impairment of endocrine, immune and behavioral functions. In this study, we evaluated the effects of CF and its metabolite, the N-nitroso derivative N-nitrosocarbofuran (NOCF), on genotoxicity, cell growth, cell cycle and apoptosis of Chinese hamster lung fibroblast (CHL) cells. NOCF, but not CF, induced genotoxicity determined by Ames test. NOCF inhibited the growth of Chinese hamster lung fibroblast (CHL) cells with an IC(50) of 12.8 microM. NOCF induced apoptosis of CHL cells, which was demonstrated by morphological changes, DNA fragmentation and flow cytometric analysis. Treatment of CHL cells with NOCF induced significant G(2)/M cell cycle arrest. Caspase-3, an executioner of apoptosis was also activated by the treatment of CHL cells with NOCF. These results suggest that NOCF, that is an important metabolite of CF, leads to the induction of cell cycle arrest and apoptosis in CHL cells.

Growth and grazing rates of the heterotrophic dinoflagellate Polykrikos kofoidii on red-tide and toxic dinoflagellates

We investigated growth rates, grazing rates, and prey selection of Polykrikos kofoidii when feeding on several species of red-tide and/or toxic dinoflagellates. Polykrikos kofoidii ingested all prey species used in this study, exhibiting positive growth on Lingulodinium polyedrum, Scrippsiella trochoidea, Ceratium furca, Gymnodinium catenatum, Gyrodinium impudicum, Prorocentrum micans, and the toxic dinoflagellate Amphidinium carterae, but not on P. minimum. Specific growth rates of P. kofoidii increased rapidly with increasing density of L. polyedrum, S. trochoidea, C. furca, and G. catenatum before saturating between 500-2,000 ng C ml(-1). Specific growth rates increased continuously when P. kofoidii was fed the other prey species. Maximum specific growth rates of P. kofoidii on G. catenatum (1.12 d(-1)), S. trochoidea (0.97 d(-1)), and L. polyedrum (0.83 d(-1)) were higher than those on C. furca (0.35 d(-1)), A. carterae (0.10 d(-1)), P. micans (0.06 d(-1)), G. impudicum (0.06 d(-1)), and P. minimum (-0.03 d(-1)). Threshold prey concentrations (where net growth = 0) were 54-288 ng C ml(-1). Maximum ingestion and clearance rates of P. kofoidii on these dinoflagellates were 5-24 ng C pseudocolony(-1) d(-1) and 1.0-5.9 microl pseudocolony(-1) h(-1), respectively. Polykrikos kofoidii strongly selected L. polyedrum over S. trochoidea in prey mixtures. Polykrikos kofoidii exhibited higher maximum growth, ingestion, and clearance rates than previously reported for the mixotrophic dinoflagellate Fragilidium cf. mexicanum or the heterotrophic dinoflagellates Protoperidinium cf. divergens and P. crassipes, when grown on the same prey species. Grazing coefficients calculated by combining field data on abundances of Polykrikos spp. and co-occurring red-tide dinoflagellate prey with laboratory data on ingestion rates obtained in the present study suggest that Polykrikos spp. sometimes have a considerable grazing impact on prey populations.

Zucchini green mottle mosaic virus is a new tobamovirus; comparison of its coat protein gene with that of kyuri green mottle mosaic virus

A novel virus we call zucchini green mottle mosaic virus (ZGMMV) was isolated from zucchini squash and its properties were determined. The size and shape of its virions, and other properties suggest that the virus is a tobamovirus. The coat protein (CP) genes of ZGMMV and kyuri green mottle mosaic virus (KGMMV), which also infects zucchini squash plants, were cloned and their nucleotides sequences were determined. The CP genes of ZGMMV and KGMMV are composed of 161 amino acid residues, and they share 77.6% amino acid identity. Western blot analysis showed that the two viruses are serologically related but not identical. Comparison of the sequences with those of sixteen other tobamoviruses revealed that the two viruses had much higher identity to cucumber green mottle mosaic virus (CGMMV), another tobamovirus infectious to cucurbit plants, than other tobamoviruses. The nucleotide and amino acid sequences of ZGMMV were from 29.5 to 78.4% and from 29.3 to 77.6% identical, respectively, to those of other tobamoviruses. The predicted virion assembly origins of the two tobamoviruses were located in the CP region of the genomic RNAs, and the predicted secondary structures were more similar to that of CGMMV than those of other tobamoviruses. The seventeen tobamo-viruses could be classified into three main subgroups based on the phylogenetic tree analysis on the CP gene, and ZGMMV and KGMMV formed a third subgroup together with CGMMV and sunn-hemp mosaic virus (SHMV). These results show that ZGMMV is a previously unknown member of the Tobamovirus genus.

Modeling of the Permeate Flux during Microfiltration of BSA-Adsorbed Microspheres in a Stirred Cell

A study on the variation of the permeate flux was performed in a stirred cell charged with microspheres, to investigate the effects of the stirrer speeds (300, 400, and 600 rpm) and the BSA concentration (0.1, 0.2, 0.4, and 0.8 g/L) under constant pressure. The permeate flux increased over time before the saturation point, but it began to decrease after that point. An increase of the BSA concentration and the stirrer speed resulted in the rapid increase of the permeate flux. This is contrary to the observation of the conventional filtration experiments using a stirred cell. A resistance-in-series model was employed for the modeling of the permeate flux. The cake resistance (R(c), induced by the concentration polarization of microspheres) and the fouling resistance (R(f), induced by the adsorption of BSA inside the membrane pore) must be considered simultaneously for the modeling. These modeling results were in good agreement with the experimental data. These can be applied to the special system considering both R(c) and R(f) as well as the general filtration systems using a stirred cell. Copyright 2000 Academic Press.

Inhibition of Helicobacter pylori hemagglutination by polysaccharide fractions from roots of Panax ginseng

Polysaccharides from the roots of Panax ginseng were extracted by hot water and fractionated by using ethanol precipitation and ion exchange chromatography. Fractions FC (crude extract), F1 (fraction precipitated by ethanol), F1N (fraction unbound to DEAE-Sepharose CL-6B), and F1A (bound fraction) were obtained. Their carbohydrate analyses showed that acidic fraction F1A contains higher amounts of galactose, arabinose and uronic acids, in comparison to FC and F1. Fraction F1N mainly consists of glucose. The inhibition of Helicobacter pylori-induced hemagglutination revealed different inhibitory activities of these fractions. In particular, acidic fraction F1A showed a remarkable inhibitory activity (minimum inhibition concentration was 0.25 mg/ml) among the polysacharide fractions. However, digestion of the fraction F1A with pectinase resulted in a lower molecular weight oligosaccharide fraction F1AP which was non-inhibitory at the concentration of 4 mg/ml. Comparison of inhibitory activities and carbohydrate compositions of isolated fractions indicates that the activity correlated with the contents of galactose, arabinose, and uronic acids. These data suggest that acidic polysaccharides may be responsible for the inhibitory activity.

Effects of partial bladder outlet obstruction and its relief on types I and III collagen and detrusor contractility in the rat

Bladder outlet obstruction induces a rapid hypertrophy characterized by increased bladder mass and collagen deposition. An increase in collagen is likely to reduce the contractility and compliance of bladder wall. This study was undertaken to investigate the effects of partial bladder outlet obstruction and its relief on types I and III collagen, and the relationship between detrusor contractility and collagen types. A total of 40 female rats was used for experiment and divided into one control, one obstruction, and three recovery groups. The contractility to field stimulation was recorded; total collagen and collagen concentration were quantified. The localization of types I and III collagen and the expression of pro-alpha1(I) and alpha1(III) collagen mRNA were determined by immunohistochemical staining and Northern blot hybridization, respectively. Contractile response to field stimulation was reduced after obstruction and recovered following relief. The total amount of collagen increased after obstruction and decreased after relief; however, collagen concentration decreased after obstruction and increased following relief. Contractility correlated negatively with total collagen but positively with collagen concentration. The protein deposition of types I and III collagen was localized in lamina propria and muscle bundles in all groups. The expression of types I and III collagen gene was up regulated after obstruction, but down regulated after relief. Negative correlation between contractility and gene expressions of collagen types was significant. These data suggest that the change in localization and quantity of collagen types leads to morphologic changes of bladder and can have an impact on the contractility of detrusor. Neurourol. Urodynam. 19:29-42, 2000.

Long-term results of percutaneous endourologic management of renal infundibular stricture

PURPOSE

The long-term result of percutaneous endourologic management in the relief of infundibular stricture is not clear. We reviewed the long-term efficacy in our series of patients.

PATIENTS AND METHODS

Twenty-seven patients underwent percutaneous endourologic management between August 1990 and February 1996. This study included the 21 who could be followed for more than 2 years (mean 4.8 years). The causes of stricture were tuberculosis (N = 18; 86%) and stone (N = 3; 14%). We made a cold-knife incision in eight patients; the others underwent only dilation with fascial dilators from 20F to 30F. Success was defined as symptomatic improvement and radiographic resolution of obstruction.

RESULTS

The overall success rate was 76% (16 of 21). Seven of the eleven patients (64%) with concomitant ureteral stricture had a successful result. In the nine patients with multiple infundibular strictures, five procedure (56%) were successful. The success rates of the cold-knife or fascial dilator were 88% (7 of 8) and 69% (8 of 13), respectively. In the five patients in whom the procedure failed, ureteral stricture was associated in four and multiple infundibular strictures in four. All of them had tuberculous infundibular strictures. No significant difference in the success rate was observed according to the duration of indwelling catheter. There was no significant complication except pyelonephritis in four patients, which was controlled with conservative treatment.

CONCLUSIONS

Percutaneous endourologic management is an effective and safe procedure to treat renal infundibular stricture. Risk factors for failure are multiple infundibular strictures and concomitant ureteral stricture. If the procedure does fail, other treatments have not been compromised. Cold-knife incision seems to be more effective than dilation.

Continuous separation of serum proteins using a stirred cell charged with carboxylated and sulfonated microspheres

We contrived a new separation system using a stirred cell charged with uncoupled microsphere similar to the chromatographic separation. Microspheres, carboxylated PS/PMAA and sulfonated PS/PNaSS, were prepared by emulsifier-free emulsion polymerization. To complement the submicron size weakness and the absence of ligands, we employed the latex form, the dispersion of microsphere, and took advantage of interaction relationships between proteins and microspheres. Adsorption isotherm is contemplated to investigate continuous separation behaviours of serum proteins. Selectivity of separation is in the following order: PS/PNaSS-2.0 (high sulfonated) < PS/PNaSS-0.3 (low sulfonated) < PS/PMAA-0.5 (low carboxylated). Unlike previous works on batch separation, not only the adsorbed amount in equilibrium (Cm), but also adsorption coefficient (K), played an important role in continuous separation. Functional groups (carboxyl and sulfonate), induced from the co-monomer, also affected the adsorption behaviours.

Collagen studies for pediatric ureteropelvic junction obstruction

OBJECTIVES

Ureteropelvic junction (UPJ) obstruction is the most common form of urinary tract obstruction in pediatrics. There is controversy regarding the need for early surgical intervention in many patients with apparent neonatal UPJ obstruction. To demonstrate the differences in type and amount of collagen in adult and pediatric UPJ obstruction, collagen studies were performed.

METHODS

The experimental groups are 9 pediatric patients with UPJ obstruction and 13 adult patients with UPJ obstruction. Six patients with normal UPJ were assigned as controls for each experimental group. The collagen content of UPJ was quantitated by hydroxyproline analysis. Immunohistochemical staining and Western blotting for collagen types I and III were performed.

RESULTS

The collagen content of pediatric UPJ was significantly lower in value than that of adult UPJ (P < 0.05). Immunohistochemical staining revealed that collagen type I was located in interfascicular space and collagen type III was located in intrafascicular space in both age groups. In Western blotting the relative intensity of collagen type III for pediatric UPJ was weaker than that of adult groups.

CONCLUSIONS

These results suggest that a larger series of patients should be examined to determine whether quantitative analysis for collagen types I and III would provide some kind of prognostic test for UPJ outcome in pediatric patients.

Percutaneous endoscopic management of upper ureteral stricture size of stent

PURPOSE

We determined the optimal size (6F versus 14/7F) of stent after endoscopic surgery based on clinical data.

MATERIALS AND METHODS

Between 1989 and 1993 we performed percutaneous endopyelotomy and endoureterotomy in 40 cases of ureteropelvic junction or upper ureteral strictures. The causes of stricture were primary in 20 cases, tuberculosis in 9, previous operation in 6 and others in 5. After endoscopic management we placed 6F internal stents in 25 patients (13 in primary and 12 in secondary cases) or 14/7F endopyelotomy stents in 15 patients (7 in primary and 8 in secondary cases) for 6 to 8 weeks (average 54.2 days). Coexisting stones or infundibular strictures were managed simultaneously. All patients have been followed for a minimum of 7 months postoperatively (range 7 to 55, average 38).

RESULTS

Overall success rate was 84% (92.3 in primary and 75% in secondary cases) with the 6F stent and 93.3% (85.7% in primary and 100% in secondary cases) with the 14/7F endopyelotomy stent.

CONCLUSIONS

The small number of patients in each group did not reach statistical significance. However, there was a definite trend for better results with the use of 14/7F stents in patients with secondary stricture (100% versus 75%), although the difference in success rates between 6F and 14/7F stents was not significant statistically (p = 0.13).

Cochlear fistula in chronic otitis media with cholesteatoma

Labyrinthine fistula in chronic otitis media with cholesteatoma most commonly involves the horizontal semicircular canal. We report three cases of cochlear fistula in chronic otitis media with cholesteatoma. All of them had a long history of otorrhea. One patient had total hearing loss of the affected side. The other two patients had conductive hearing loss. Radical mastoidectomy had been done in all cases. Cholesteatoma in the tympanic cavity destroyed the basal turn of the cochlea. These fistulas were sealed with muscle or Gelfoam with streptomycin. We found no fistula in the semicircular canal in any of the three cases. We report three cases of cochlear fistula in chronic otitis media with cholesteatoma, and review the literature.